Biomimetic Synthesis of Lepidocrocite on Marine Spongin Scaffolds: Mechanistic Insights and Multifunctional Potential

Introduction

In 1968¹, a significant milestone in marine biomineralogy was achieved through the observation of crystalline lepidocrocite mineral phases (γ-FeOOH) forming on the proteinaceous spongin fibers of marine demosponges. This finding laid the foundation for exploring the field of biomimetics, raising intriguing questions about the potential of marine sponges as a sustainable source of unique spongin-based 3D scaffolds suitable for the in vitro biomineralization of iron ions on and within their microporous surfaces².

Methods

Our recent advancements have employed cutting-edge biomimetic techniques to synthesize lepidocrocite in vitro on a spongin scaffold ³. This research study explores the complex interaction between iron ions and the spongin scaffold in an artificial seawater environment, resulting in the development of a centimeter-large 3D iron–spongin composite. It is analyzed using analytical techniques including digital optical microscopy, scanning electron microscopy (SEM/EDX), high-resolution transmission electron microscopy (HRTEM), FTIR, X-ray diffraction, and confocal micro X-ray fluorescence spectroscopy (CMXRF).

Results

Our research reveals a likely mechanism for lepidocrocite formation, seemingly linked to the amino acid functional groups in spongin. Building on this insight, we developed an iron–spongin composite characterized by its porosity, macroscopic 3D structure, and magnetic properties, as confirmed by comprehensive analyses using various techniques. Moving beyond merely providing foundational knowledge, our study pioneers the application of this 3D composite as a dopamine sensor. This represents not just a breakthrough in sensor technology but also exemplifies the effective translation of a biological process into a practical engineering application.

Conclusions

We successfully synthesized the 3D iron–spongin composite in vitro, leveraging the unique properties of spongin and its interaction with iron. This innovative material demonstrates significant potential as a novel dopamine sensor, highlighting its broader applicability in fields such as environmental remediation, biomedical engineering, and electrochemical devices, thereby exemplifying the seamless integration of biomimetic research with practical engineering solutions.